1. Field of the Invention
The present invention relates to a printer that separates a single cut sheet from a stack of cut sheets, feeds the separated sheet and prints on the cut sheet. A printer of the present invention provides a printing head to print on the cut sheet at a printing position and a pair of sending rollers to send the cut sheet to the printing position. The printer of the present invention can control the position of the cut sheet when the cut sheet begins to be sent to the printing position, and can control a relationship between the timing of when to begin sending the cut sheet to the printing position and the timing of when to have the printing head begin a printing operation. According to the printer of the present invention, a relationship between a print start position on the cut sheet and a leading edge of the cut sheet can be adjusted to a desired relationship, and printing can be performed on a desired location of the cut sheet. Printing can also be performed without leaving a margin along the leading edge of the cut sheet.
The present invention also relates to a method of controlling a printer for adjusting a position of a cut sheet to a desired position when the cut sheet begins to be sent towards a printing position.
The printer of the present invention is not limited to a printing machine exclusively for printing, such as an inkjet printer or a laser printer. The printer of the present invention may be built into a copy machine, a fax machine, or a multifunctional machine, and includes a mechanism within these machines to print pictures and/or characters on the cut sheet.
2. Description of the Related Art
A printer that pulls out a single cut sheet from a stack of cut sheets, feeds the pulled out cut sheet, sends the fed cut sheet to a printing position and prints on the cut sheet at the printing position is known. This type of printer provides a feeder to pull out the single cut sheet from the stack of cut sheets and feed the cut sheet, a pair of sending rollers to send the cut sheet fed from the feeder towards the printing position, and a printing bead to print on the cut sheet sent to the printing position by the sending rollers.
An art for controlling the position of the cut sheet when the cut sheet begins to be sent to the printing position is known, wherein the art stops or reverses a rotating direction of the pair of sending rollers, which sends the cut sheet to the printing position, and feeds the cut sheet to that pair of sending rollers. When the cut sheet is fed towards the stationary or reverse-rotating sending rollers, a leading edge of the cut sheet becomes positioned in a predetermined position where the sending rollers contact. The leading edge of the cut sheet is aligned along a contacting line between the sending rollers. When the pair of sending rollers begins to rotate in the standard direction, the cut sheet with the leading edge positioned in the predetermined position begins to be sent to the printing position at a desired timing. According to this art, a position of the cut sheet when the cut sheet begins to be sent to the printing position can be controlled to a fixed position, and a position of the cut sheet when a printing operation begins with the printing head can be controlled to a desired position. According to this type of printer, a relationship between a print start position on the cut sheet and the leading edge of the cut sheet can be adjusted to a desired relationship, and printing can be performed on a desired location of the cut sheet. Printing can also be performed without leaving a margin along the leading edge of the cut sheet when a margin-less printing mode is desired.
This type of printer is described in Japanese Laid-Open Patent Application Publication No. 1998-254202. This printer provides an image creation mechanism to create a transferable printing image and a transfer printing mechanism (corresponds to the printing head of the present invention) to transfer the transferable printing image produced by the image creation mechanism to the cut sheet. This printer further provides a feeder to pull out a single cut sheet from a stack of cut sheets and feed the pulled out cut sheet, a pair of sending rollers to send the cut sheet fed from the feeder to a printing position (in this case a transfer printing position), and a sensor positioned on an upstream side of that sending rollers. The sensor detects a timing that the leading edge of the cut sheet, fed towards the sending roller from the feeder, reaches a position to face the sensor.
This printer begins reducing the feeding speed of the feeder at a timing when the leading edge of the cut sheet is detected by the sensor, and decelerates to a feeding speed of zero after a predetermined period. The decelerating pattern is designed so that the following phenomenon occurs. That is, after the leading edge of the cut sheet has been positioned upon contacting the sending rollers, the feeder feeds the cut sheet further and the feeding operation is stopped before the cut sheet is substantially curved. If the cut sheet is substantially curved, it generates noise because the curved cut sheet hits a guide board that guides the cut sheet. The printer described in Japanese Laid-Open Patent Application Publication No. 1998-254202 prevents the noise from generating by beginning the deceleration of the feeding speed of the cut sheet before the leading edge of the cut sheet contacts the sending rollers.
The printer described in Japanese Laid-Open Patent Application Publication No. 1998-254202 switches the time it takes, depending on the size of the cut sheet, for the feeding speed to become zero once it begins to decelerate. The tendency to curve varies depending on the size of the cut sheet, and when the deceleration pattern is switched according to the site of the cut sheet, the noise generated by the cut sheet hitting the guide board can be contained within a predetermined level, even if the size of the cut sheet varies.